“I’m feeling disbelief. I’m still waiting for them to call and they won’t,” Greg said. “They were good friends. If you needed them, they were there.”

Greg said the two friends were living together in the home to the left of the house that the explosion originated in. He said one was 26 and the other was 30 but would not give their names. The 26-year-old owned the house and the 30-year-old was staying there. The 26-year-old’s fiancée and stepson were also home at the time of the explosion.

Both survived the blast.

Deputy police chief Darryl da Costa said homicide detectives are leading the investigation because it’s still unclear why the explosion happened and the deaths are being treated as suspicious.

“I’m told by investigators that there’s no indication at this point that the blast was caused by an explosive device or a drug lab,” da Costa said. “However, the investigation remains active and ongoing.”

He said it may take days or weeks to pinpoint the cause and residents who were displaced will be allowed back into their homes as soon as they’re deemed safe. Da Costa couldn’t say how long that might take.

“These events are horrific events as we all know and it’s horrific to see, not just the physical damage but the emotional damage that so many people in this part of the city (are experiencing),” said Mayor Stephen Mandel from the site known to emergency crews as Ground Zero. “Our thoughts and prayers go out to them.”